Project description:The cultivated almond exhibits self-incompatibility of the gametophytic type regulated by the S-locus, and expressed in pistil (S-RNase) and in pollen (SFB protein). The aim of this study is to clarify the transcription pattern of these 2 S-genes and to identify additional components of the gametophytic self-incompatibility system in almond. With this aim, A2-198 (self compatible) and ITAP-1 (self incompatible) almond selections were used: RNA-seq of pistils of these two accessions both un-pollinated and pollinated with A2-198 pollen were carried out.
Project description:Plum pox virus (PPV) causes the serious sharka disease in Prunus trees. Peach [P. persica (L.) Batsch] trees are severely affected by PPV and no definitive source of genetic resistance has been identified at this moment. Previous results showed, however, that PPV-resistant ‘Garrigues’ almond [P. dulcis (Mill.) D.A. Webb] was able to transfer its resistance to ‘GF305’ peach through grafting, preventing these trees from PPV infection and reducing symptomatology and viral load in PPV-infected plants. A recent study tried to identify genes responsible for this effect by studying mRNA expression through RNAseq data in peach and almond plants, before and after grafting, and before and after PPV infection. In this work, we used the same peach and almond samples, but focused the high-throughput analyses on small RNAs (sRNAs) expression. We studied massive sequencing data and found an interesting pattern of sRNAs overexpression linked to antiviral defense genes that suggested activation of these genes followed by downregulation to basal levels. We also discovered that ‘Garrigues’ almond plants were infected by different plant viruses that were transferred to peach plants. The large amounts of viral sRNAs found in grafted peaches indicated a strong RNA silencing antiviral response and led us to postulate that these plant viruses could be collaborating by cross-protection in the observed ‘Garrigues’ effect.
